Arrangement for the feeding of gaseous tubes



March 27, 1934. B. c. w. HAGELIN 1,952,246

ARRANGEMENT, FOR THE FEEDING OF GASEOUS TUBES Filed NOV. 22, 1932 Patented Mar. 27, 1934 UNITED STATES ARRANGEMENT FOR THE FEEDING OI GASEOUS TUBES Boris Cesar Wilhelm Hagelin, Stockholm, Sweden Application November 22, 1932, Serial No. 643,944

- In Sweden December 16, 1931 7. Claims.

For electric lighting equipments, employing gaseous tubes, as neon tubes, several different systems are hitherto used in connection with the' arrangement or design of the transformer or 5 transformers which supply the high tension needed for feeding the tubes.

One way is to use a single transformer of normal type to which all the tubes are connected in a single series or in a number of parallel series. Another method makes use of a plurality of transformers of the type having a magnetic shunt, in whichcase there is connected a series of tubes or a single tube to each transformer.

As gaseous tubes are of a strongly pronounced negative characteristic, a considerable impedance is needed in the feeding circuits in order to keep the current at a constant and ,desired value. This is necessary to maintain a uniform light intensity in the individual tubes. Theimpedance may be obtained either by ohmic resistances or by reactance coils inserted in the primary or secondary circuits of the transformers in case oftransformers of normal type, or by the use of magnetic shunt transformers.

In order to allow regulation of the current, the resistances or the reactance coils, or the magnetic shunts are made variable. If desired,

special connections of reactances and condensers, or condensers only, may be used in order to oba current regulation.

,All the regulating methods above indicated sufier from certain disadvantages. 'The' cost of manufacture of the apparatus is high and .so is the power consumption too. Where separate transformers are used for each individualtube the tranqlormer cost will be high, while in case of a sin le transformer common to all tubes or series of tubes the cost of high-tension cables will be high. Several attempts have been made to reduce the cost of installation as well as the power consumption. v

According to one proposal, which relates to the used a separate transformer for each tube, the transformers have been placed as near as possible to the tubes, or built into the respective tubes, in order to reduce the cost of cables to a minimum. In such case, however, the transformer cost will still remain high, as the individual transformers must be equipped with means to permit regulation of the current according to one or other of the-methods stated above. Another disadvantage inherent to the above stated methods is that the regulation of different tubes '55 of one sign is a tedious and slow procedure.

tain maximum power factor or facilitate the- The object of this invention is to overcome the above disadvantages by the provision of an arrangement which enables reduction of the high tension cables to a minimum, simplifies the regulation, and reduces the cost of the equipment and so the consumption of energy.

The invention is characterized, chiefly, by the provision of two or more transformers, whose primary coils are connected in series and whose secondary coils are connected to separate tubes 05 or series of tubes. The transformers used are of the normal type with a closed magnetic circuit and of high efliciency, and for all the transformers belonging to the same sign only one regulating apparatus is required. As transformers with small magnetic losses have a, practically, constant ratio between the primary and the secondary currents, it follows that the current in the tubes connected to the transformers of the same series will Joe-the same, provided the ratio between the primary and secondary turns of all the transformers is the same. This constant ratio is maintained until the saturation point has been reached, and, as a result, tubes of different lengths may be connected to transformers of 30 identical size. This series connection possesses the inherent characteristic that the voltage and power consumed by the individual transformers will be in proportion to the requirements of the tubes connected to them. To regulate and limit 35 the current to a predetermined value some of the already known methods may be used, if desired, in connection with means to obtain maximum power factor.

It will bereadily understood that if the transformer ratios and the regulating equipment are suitably calculated only that minimum of energy need be lost which is unavoidable to obtain the necessary regulation.

On the annexed drawing, Figs. 1 to 7 show different ways of carrying this invention into effect.

Fig. 1 is a diagram of connections showing the principle of the invention, without regulating equipment. Here 1, 2, 3 designate separate series of tubes, comprising one, one and two tubes,'respectively, although the number of tubes in each series may be chosen arbitrarily. Each series is connected to the secondary of separate transformers 4, 5, 6, respectively, which are of normal type, without magnetic shunt. The primary coils of the transformers are connected in series with each other, and are connected by the conductors 9 to the terminals 7, 8 of the electric supply.

Figs. 2 to 7 show the same diagram as Fig. 1,

'to the s'econda with different regulating apparatus added. In Fig. 2 a transformer 10 is shown inserted between the supply and the tube transformers, with regulating taps on the primary and secondary windings.

According to Fig. 3 the regulating apparatus consists of a combination of reactance coils 11, 11 and a condenser 12, connected in the primary circuit of the tube transformers, or eventually in the primary of the intermediate transformer 10, shown by dotted lines. Fig. 4 shows an ohmic resistance 13 and Fig. 5 a reactance coil 14 as regulating apparatus.

According to Figs. 6 and 7, a transformer having a magnetic shunt 15 is used, in Fig. 6 alone, in Fig. 7 together with a condenser 12.

Other arrangements may also be used for the regulation of series-connected tube transformersfiwithout departing from the principle of the invention.

In all the difierent arrangements possible, the transformer ratios are chosen according to operating exigencies. If all tubes in the same sign are to operate with the same current intensity, the transformers shall all have the same ratio. It, on the other hand, some tubes are to operate with another current intensity than the others, then the ratio of the transformers for said flrstmentioned tubes must be chosen with a view to producing this current.

If the sign consists of separate letters, then each letter may have a separate transformer. In such case several different transformer sizes may be used suited to the difierent lengths of the tubes, and thus to the energy and voltage requirements of the tubes. Yet, however, it is not necessary to match the transformers very carefully, as long as the transformers are not overloaded, because every transformer will automatically deliver exactly the appropriate voltage for its respective tube.

If under certain circumstances it would not be suitable to use one transformer for each in dividual letteryonly such a number of transformers is used as is necessary to prevent the secondary voltage from growing higher than is suitable from a reliability standpoint.

WhatIclaim is:-

lnAn arrangement for operating gaseous tubes, comprising a set of tube groups each comprising one or more tubes, a separate electric transformer with a closed magnetic circuit for each of said groups, with each group connected to the secondary circuit of the respective transformer, and a single feeding circuit containing a series connection of the primary coils of all the transformers.

2. An arrangement for operating gaseous tubes, comprising a set of tube groups each group comprising one or more tubes, a separate electric transformer with a closed magnetic circuit for each tube group 'th each tube group connected circuit of the respective transformer, a single feeding circuit containing a series aeeaaec connection of the primary coils of all the transformers, andcurrent' controlling means in said feeding circuit to obtain a constant current through the transformer series, independently of the voltage requirements of the individual tubes.

3. An arrangement for operating gaseous tubes, comprising a set of tube groups eachgroup comprising one or mpre tubes, a separate electric transformer with closed. magnetic circuit for each tube group with each tube group connected to the secondary circuit of the respective transformer, a single feeding circuit containing a series connection of the primary coils of all the transformers, means in said feeding circuit to control the current, and other means in the feeding circuit to control the power factor.

4. An arrangement for operating gaseous tubes, comprising a set of tube groups each comprising one or more tubes, a separate electric transformer with closed magnetic circuit for each tube group with each tube group connected to the secondary circuit of the respective transformer, a single feeding circuit containing a series connection of the primary coils of all the transformers, and a reactance coil in said feeding circuit.

5. An arrangement for operating gaseous tubes, comprising a set of tube groups each comprising one or more tubes, a separate electric transformer with closed magnetic circuit for each tube group with each tube group connected to the secondary circuit of the respective transformer, a single feeding circuit containing a series connection of the primary coils of all the transformers, and a combination of reactance coils and condenser in said feeding circuit.

6. An arrangement for operating gaseous tubes, comprising a set of tube groups each comprising one or more tubes, a separate electric transformer with closed magnetic circuit for each tube group with each tube group connected to the secondary circuit of the respective transformer, a single feeding circuit containing a series connection of the primary coils of all the transformers, an intermediate transformer inserted in said feeding circuit so that its secondary coil is in series with said series connection of the primary coils of the tube transformers, and a reactance coil connected in the primary circuit of said intermediate transformer.

'7. An arrangement for operating gaseous tubes, .125

comprising a set of tube groups each comprising one or more tubes, a separate electric transformer with closed magnetic circuit for each tube group with each tube group connected to the secondary circuit of the respective transformer, a single feeding circuit containing a series connection of the primary coils of all the transformers, an intermediate transformer inserted in said feeding circuit so that its secondary coil is in series with said series connection of the primary coils of the tube transformers, and a combination of reactance coils and condenser connected in the pri-,

mary circuit of said intermediate transformer.

BORIS CESAR WILHELM HAGELIN. 

